Working papers

Crash Risk in Individual Stocks

In this study, I develop a novel methodology to extract crash risk premia from options and stock markets. I document a dramatic increase in crash risk premia after the 2008/2009 financial crisis, indicating that investors are willing to pay high insurance to hedge against crashes in individual stocks. My results apply to all sectors but are most pronounced for the financial and industrial sectors. At the same time, crash risk premia on the market index remained at pre-crisis levels. I theoretically explain this puzzling feature in an economy where investors face short-sale constraints. Under short-sale constraints, prices are less informationally efficient which can explain the increase in downside risk in individual stocks. In the data, I document a strong link between proxies of short-sale constraints and crash risk premia.

Using a fast numerical technique, we investigate a large database of investor suboptimal non-exercise of short maturity American call options on dividend-paying stocks listed on the Dow Jones. The correct modelling of the discrete dividend is essential for a correct calculation of the early exercise boundary as confirmed by theoretical insights. Pricing with stochastic volatility and jumps instead of the Black-Scholes-Merton benchmark cuts by a quarter the amount lost by investors through suboptimal exercise. The remaining three quarters are largely unexplained by transaction fees and may be interpreted as an opportunity cost for the investors to monitor optimal exercise.